To love the novels of Cesar Aira you must have a taste for the absurd, a tolerance for the obscurely philosophical and a willingness to laugh out loud against your better judgment. His latest novel to be translated into English, The Hare, is set in the Argentine pampas at the end of the 19th century. But don't let any veneer of realism fool you. Despite its gauchos, Indians and lyrical descriptions of Argentina's sprawling plains, The Hare doesn't approach the accuracy of An Episode in the Life of a Landscape Painter, Aira's last pampas novel to be published here. It's more like an episode of Star Trek, crossed with Lawrence of Arabia.

As in so many of Aira's novels, the hero is an earnest man with a faintly ridiculous mission. Tom Clarke, a British geographer and naturalist, roams the pampas in search of a mythical rabbit that not only jumps but flies. With him ride two Argentine sidekicks: a chatty 15-year-old boy and a taciturn gaucho with his own secret mission. Together the three horsemen visit a series of Indian tribes, becoming more and more entangled in local politics until Clarke is declared commander-in-chief of an Indian confederation and the region erupts in war. Near the book's climax, the Englishman strips off his clothes, dons Indian greasepaint, and watches a flock of giant ducks usher an enormous egg into the ocean.

Even that bizarre synopsis is too solemn for Aira's novel. From The Hare's first chapter, when a drunken dictator pirouettes on the back of a galloping horse, the plot is only loosely attached to logic. Clarke's journey through the pampas resembles a vast space voyage: long rides through desolate landscape punctuated by conversations with extraordinary grotesques. One of the tribes he meets lives underground, indulging in promiscuous sex and bartering coal for liquor. Another speaks in "monstrous sentences" designed to be incomprehensible. For better or worse, such tribes are more ontological experiments than historical re-creations. And Clarke himself is hardly more rational. His war-winning battle strategy? It's "the Great Sine Curve of the Mapuche armies, a line that would have exploded the maps if anyone had tried to trace it."

Aira fans know that such outlandish B-movie fantasies are all part of the game. Unlike many contemporary novelists, who pride themselves on carefully polished stories, Aira incorporates chance and improvisation in his work. He writes only one page a day and never revises. Though his fifty-odd novels vary in tone and effect — some are somber, some are even political — his best-known works are nonsensically hysterical. In How I Became a Nun, a melancholy boy drowns in a vat of ice cream. In The Literary Conference, a mad scientist attempts to clone the Mexican novelist Carlos Fuentes.

Yet to enter Aira's world through comedy can be disorienting. The winking tone, the rapid plot shifts, the matter-of-fact absurdity can give new readers a swooning sense of instability. The Hare makes the flat, monotonous pampas as strange and unpredictable as Wonderland. In classic Aira fashion, even the book's hero has trouble making sense of events. At one point, Clarke's guide contends that the hare he's searching for isn't an animal at all, but rather a diamond. Such shape-shifting prompts Clarke to reflect:

Everything that happened, isolated and observed by an interpretive judgement, or even simply by the imagination, became an element that could then be combined with any number of others. Personal invention was responsible for creating the overall structure, for seeing to it that these elements formed unities.

In one man's "unity," the hare is a magnificent mammal. In another's, it's the foundation of a family fortune. As perspective shifts, so does meaning. Reality is no more trustworthy than interpretation; logic itself is a kind of fraud.

The dramatization of these subversive ideas has been Aira's central preoccupation for decades, and in The Hare he achieves one of his most brilliant, hilarious articulations yet. The novel is not without its flaws — I'm sad to report that both its major villains are "black as an African," and its overt equation of the Indian with the irrational makes my conscience queasy. But if you can set such quandaries aside, you'll find there are few adventures more outrageous, and more unsettling, than this cowboy chase through the pampas in search of the white rabbit.